Apoptotic changes in the myocardium in the course of experimentally-induced pleurisy

The secreted proinflammatory interleukins IL-1, IL-6 and TNF in the course of experimentally-induced pleurisy can be the cause of pathological changes in the ultrastructure of cardiac muscle and of apoptosis. The pleurisy was induced in rats by means of carrageenin. The scraps of cardiac muscle obtained during the inflammatory reaction in the pleura were analysed by means of an electron microscope. The scraps were also stained with the TUNEL method in order to find the apoptotic foci. It was proved by the experiment that the inflammatory process affected mitochondria in the cardiomyocytes, enhanced collagen fibre synthesis and contributed to the formation of apoptotic foci in the cardiac muscle

Electrocardiography and echocardiography in athletic heart imagining

The aim of the study was evaluation of electrocardiographic and echocardiographic parameters in athletes. „Athletic heart” characteristics were compared with fit persons’ heart. 96 athletes participated in the study. Sportsmen were divided into: static (S), dynamic (D) and composite (SD) exercise groups and Polish (I), European (II), World (III) champions. 30 students from Sport Academy formed the control group (K). Electrocardiographic and echocardiographic examination were performed in everyone. As regards the type of exercise, the end-systolic left ventricular (LV) dimension was smaller in S in comparison with D and SD (28.9 vs 32.2 and 32.68 mm; P<0.05). LV mass was bigger in D in comparison with K (273.2 vs 218.6 g; P<0.05). Medium Pulmonary Artery Pressure (MPAP) in S and SD was lower in respect to D and K (11.75; 11.08 vs 15.52; 17.43 mm Hg; P<0.05). We observed lower heart rate in D, SD in comparison with K (58.64; 60.54 vs 68.8; P<0.05), bigger R wave amplitude in V5 (RV5) (21.65; 23.5 vs 15.03 mm; P<0.05) and V6 (RV6) (23.5 vs 15.3 mm; P<0.05) in group S in respect to K. LV mass was bigger in III than in K (261.3 vs 218.6 g; P<0.05). MPAP was lower in I and II in comparison with K (11.42; 13.13 vs 17.43 mmHg; P<0.05). HR was lower in categories I, II than in K (61.32; 60.13 vs 68.8; P<0.05), RV5 was bigger in I in comparison with K (19.5 vs 15.03 mm; P<0.05). The electrocardiography and echocardiography proves to find some significant differences between athletic and fit persons’ heart especially as concerns MPAP, RV5, RV6 values

A quantitative thermal analysis of cyclists’ thermo-active base layers

It is well known that clothes used in sporting activity are a barrier for heat exchange between the environment and athlete, which should help in thermoregulation improvement. However, it is difficult to evaluate which top is best for each athlete according to the characteristics of the sport. Researchers have tried to measure the athlete’s temperature distribution during exercise at the base layers of tops with different approaches. The aim of this case study was to investigate the use of thermography for thermo-active base layer evaluation. Six new base layers were measured on one cyclist volunteer during a progressive training on a cycloergometer. As a control condition, the skin temperature of the same volunteer was registered without any layer with the same training. A training protocol was selected approximate to cycling race, which started from the warm-up stage, next the progressive effort until the race finished and at the end ‘‘cool-down’’ stage was over. In order to show which layer provided the strongest and weakest barrier for heat exchange in comparison with environment, the temperature parameters were taken into consideration. The most important parameter in the studies was the temperature difference between the body and the layers, which was changing during the test time. The studies showed a correlation between the ergometer power parameter and the body temperature changes, which has a strong and significant value. Moreover, the mass of every layer was checked before and after the training to evaluate the mass of the sweat exuded during the test. From this data, the layer mass difference parameter was calculated and taken into consideration as a parameter, which may correspond with the mean heart rate value from each training. A high and positive correlation coefficient was obtained between the average heart rate and the mass difference for the base layers. Thermal analysis seems to have a new potential application in the objective assessment of sports clothing and may help in choosing the proper clothes, which could support heat transfer during exercising and protect the body from overheating

Secular trends: a ten-year comparison of the amount and type of physical activity and inactivity of random samples of adolescents in the Czech Republic

BACKGROUND: An optimal level of physical activity (PA) in adolescence influences the level of PA in adulthood. Although PA declines with age have been demonstrated repeatedly, few studies have been carried out on secular trends. The present study assessed levels, types and secular trends of PA and sedentary behaviour of a sample of adolescents in the Czech Republic. METHODS: The study comprised two cross-sectional cohorts of adolescents ten years apart. The analysis compared data collected through a week-long monitoring of adolescents' PA in 1998-2000 and 2008-2010. Adolescents wore either Yamax SW-701 or Omron HJ-105 pedometer continuously for 7 days (at least 10 hours per day) excluding sleeping, hygiene and bathing. They also recorded their number of steps per day, the type and duration of PA and sedentary behaviour (in minutes) on record sheets. In total, 902 adolescents (410 boys; 492 girls) aged 14-18 were eligible for analysis. RESULTS: Overweight and obesity in Czech adolescents participating in this study increased from 5.5% (older cohort, 1998-2000) to 10.4% (younger cohort, 2008-2010). There were no inter-cohort significant changes in the total amount of sedentary behaviour in boys. However in girls, on weekdays, there was a significant increase in the total duration of sedentary behaviour of the younger cohort (2008-2010) compared with the older one (1998-2000). Studying and screen time (television and computer) were among the main sedentary behaviours in Czech adolescents. The types of sedentary behaviour also changed: watching TV (1998-2000) was replaced by time spent on computers (2008-2010).The Czech health-related criterion (achieving 11,000 steps per day) decreased only in boys from 68% (1998-2000) to 55% (2008-2010). Across both genders, 55%-75% of Czech adolescents met the health-related criterion of recommended steps per day, however less participants in the younger cohort (2008-2010) met this criterion than in the older cohort (1998-2000) ten years ago. Adolescents' PA levels for the monitored periods of 1998-2000 and 2008-2010 suggest a secular decrease in the weekly number of steps achieved by adolescent boys and girls. CONCLUSION: In the younger cohort (2008-2010), every tenth adolescent was either overweight or obese; roughly twice the rate when compared to the older cohort (1998-2000). Sedentary behaviour seems relatively stable across the two cohorts as the increased time that the younger cohort (2008-2010) spent on computers is compensated with an equally decreased time spent watching TV or studying. Across both cohorts about half to three quarters of the adolescents met the health-related criterion for achieved number of steps. The findings show a secular decrease in PA amongst adolescents. The significant interaction effects (cohort × age; and cohort × gender) that this study found suggested that secular trends in PA differ by age and gender